Collector brushes for slip contacts



- Jan. 21, 19691 H. DRESCHER 3,423,715

COLLECTOR BRUSHES FOR SLIP CONTACTS:

Filed Sept. 15, 1966 v I INVENTOR nsmz onsscnzn AGENT United StatesPatent COLLECTOR BRUSHES FOR SLIP CONTACTS Heinz Drescher, Hamburg,Germany, assignor to North American Philips Company, Inc., New York,N.Y.,

a corporation of Delaware Filed Sept. 15, 1966, Ser. No. 579,540

US. Cl. 339-1 Int. Cl. Htllr 39/38 Claims ABSTRACT OF THE DISCLOSURE Theinvention relates to a contact brush for slip contacts in particular forcontact strips or rings varying their direction of movement.

For transmitting low voltages, for example, of measured values, wirehair brushes have proved of particular advantage since they ensure a lowand in particular constant contact resistance with the slip ring. Ofcourse the wires of the brush in such collectors assume an inclinationwhich corresponds to the relative motion. In these known brushesdifficulties are experienced when the direction of movement is reversedas a result of which the wires run against the grain and are upsetuntil, usually accidentally, they tip over and consequently adapt,although deformed, to the new direction of movement with a decreasedfrictional resistance.

It will be clear that as a result of this, in particular when thedirection of movement varies frequently, the lifetime of the brushes isstrongly reduced.

This drawback is avoided according to the invention in that the brush issecured inside a brace so as to be resilient and movable in the axialdirection.

In order that the invention may readily be carried into effect, it willnow be described in greater detail, by way of example, with reference tothe accompanying drawing.

In the curves of a brace 1 which preferably consists of metal, twostrips 2, 2' of a soft, flexible material, for example, rubber or thelike, are secured which are provided with conductive surface 3, 3'. Suchsurfaces may consist for example of thin copper foil or may be providedin a different manner. At the open end of the brace 1, the strips 2, 2',the foils 3, 3', and the brush 4 are secured together so as to beconductive, for example, by soldering, and are held together, ifrequired, by a clamp 5.

At the transverse portion of the brace 1 a threaded tag ice 6 isprovided which is passed through the aperture 7 of the protective cap 8and is secure-d by the nut 9'. The supply lead can be connected to thethreaded tag 6. Two guide pins 10 serve for securing the assembly in thecollector device, the construction of which, however, does not form partof the present invention.

If during a reversal of the direction of movement between the slidingring and the brush, or as a result of an unevenness of the sliding ring,an axial force acts upon the brush 4, said brush, as a result of itsflexible suspension, is capable of moving into the brace 1, the strips2, 2 rolling up on the inside of the brace limbs. As a result of thelong spring path, the pressing force of the brush against the slidingring remains substantially constant.

What is claimed is:

1. A collector brush assembly comprising a substantially U-shaped framemember having a yoke portion and two arm portions, first and secondflexible strip members each extending from the extremity of a respectivearm portion, said strip members being arranged with their extending endsin spaced confronting relationship, and a collector brush memberinterposed between the said extending ends of said strip members.

2. A collector brush assembly as claimed in claim 1 wherein said stripmembers each comprise a flexible rubber-like band and an electricalconductive coating on said band.

3. A collector brush assembly as claimed in claim 2 wherein saidconductive coating consists of a metal foil.

4. A collector brush assembly as claimed in claim 1 wherein the saidextending ends of said strip members are positioned with their outersurfaces in confronting relationship with the said brush memberinterposed and extending beyond the said confronting portions.

5. A collector brush assembly as claimed in claim 1 further comprising ahousing member enclosing said frame member and electrical terminal meanssecured to said frame member and extending through said housing member.

References Cited UNITED STATES PATENTS 466,448 1/ 1892 Sprague 310-244-1,878,323 9/1932 Quist 339-1 2,905,924 9/ 1959 Peterson 339-1 3,172,9823/1965 Reed 339-1 3,252,248 5/ 1966 Zalkind 339-1 2,242,273 5/ 1941Taylerson 339-8 2,742,617 4/ 1956 Bondley 339-9 FOREIGN PATENTS 357,3629/ 1931 Great Britain.

RICHARD E. MOORE, Primary Examiner.

US. Cl. X.R. 339-149; 310-248 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3,423,715 January 21, 1969 Heinz Drescher It iscertified that error appears in the above identified patent and thatsaid Letters Patent are hereby corrected as show below:

In the heading to the printed specification, between lines 6 and 7,insert Claims priority, application Germany, Nov. 13, 1965, P262 11Signed and sealed this 10th day of March 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer

